Dr. Hannah Loranger

Staff until 2016

Contact

Email: hannah.loranger(at)uni-oldenburg.de

Project and Research Interests:

In my project, funded by the DFG, I study the effects of different climatic factors on germination, establishment and further development of different tree species forming alpine tree lines in Europe.

Specific questions are:

  • How does temperature influence germination of the study species?
  • How do the duration of snow cover / the length of the growing season affect germination, growth and survival of the different tree species?
  • What is the effect of warmth, frost and radiation stress, especially with regard to interactions of (1) low night temperatures and high solar radiation the following day (photochilling) and (2) increased day temperatures and drought (more beneficial growth temperatures vs. drought stress)?
  • How respond different taxa (4 tree species: Larix decidua, Picea abies, Pinus cembra, Sorbus aucuparia) and different functional types (2 evergreen vs. 2 deciduous, 3 coniferous vs. 1 broad-leafed) towards climatic stressors at the tree line?

Publications

Loranger J, Meyer ST, Shipley B, Kattge J, Loranger H, Roscher C & Weisser WW. 2012. Predicting invertebrate herbivory from plant traits: evidence from 51 grassland species in experimental monocultures. Ecology 93: 2674-2682.

Loranger J, Meyer ST, Shipley B, Kattge J, Loranger H, Roscher C, Wirth C & Weisser WW. 2013. Predicting invertebrate herbivory from plant traits: Polycultures show strong nonadditive effects. Ecology 94(7): 1499-1509.

Loranger H, Weisser WW, Ebeling A, Eggers T, De Luca E, Loranger J, Roscher C, Meyer ST. 2014. Invertebrate herbivory increases along an experimental gradient of grassland plant diversity. Oecologia 174(1): 183-193.

Bader M, Loranger H & Zotz G. 2014. A cool experimental approach to
explain elevational treelines. But can it explain them? American Journal
of Botany
101: 1403-1408.

Loranger H, Zotz G & Bader M. 2016. Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions. AoB Plants, 8: plw053.

Loranger H, Zotz G & Bader MY. 2017. Competitor or facilitator? The ambiguous role of alpine grassland for the early establishment of tree seedlings at treeline. Oikos, 126: 1625-1636.

 

 

Curriculum Vitae

10.2005 - 03.2011 Studies of biology at the University of Osnabrück

08.2007 - 07.2008 Exchange studies (biology) at the University of Sherbrooke, Quebec, CA

05.2010 - 03.2011 External diploma thesis in the framework of the Jena-Experiment (University of Jena): "Increasing invertebrate herbivory in an experimental grassland plant diversity gradient"

07.2011 - 09.2011 Research assistant at the Institute of Ecology, University of Jena

10.2011 - 05.2016 Dissertation at the University of Oldenburg: "The regeneration niche of trees at the alpine tree line: climatic constraints on germination and seedling establishment"